1. Field of the Invention
The present invention relates to an assembly structure of a flat type device and method for assembling the same. More specifically, the invention relates to an assembly structure of a flat type device including a panel having electrode terminals disposed on a peripheral portion thereof, such as liquid crystal, EL, plasma, and other panels.
2. Description of the Prior Art
Among various types of panels, a liquid crystal panel is described here. As shown in FIGS. 55 and 56, which are perspective and sectional views of a prior art, a liquid crystal panel 320 is in general so structured that liquid crystals 321 are sealed in between a pair of glass substrates 301, 302 and a large number of electrode terminals 303 are disposed on a peripheral portion of one glass substrate 302. FIG. 56 shows a section as viewed along the line A-A' in FIG. 55. In its assembled state, the liquid crystal panel 320 has on a peripheral portion thereof: flexible wiring boards 304, 304', . . . each having a drive IC 305 mounted thereon for driving the liquid crystal panel 320; a generally L-shaped common wiring board 307 for receiving signals from external; and a generally rectangular control board 311 for feeding signals to the common wiring board through a connector 308 (the assembled panel is referred to as a "module"). As shown in FIG. 55, the common wiring board 307 has, on its one surface, a bus line (circuit wiring) 371, and electrode terminals 372 electrically conducting with the bus line 371 and corresponding to the flexible wiring boards 304, 304', . . . , respectively. As shown in FIG. 56, the flexible wiring board 304 has a wiring layer, which includes output terminals 342 and an input terminal 306, provided on a base material surface 340 having a flexibility. The drive IC 305 is connected to the wiring layer by bump electrodes 305a, 305b (numeral 396 denotes resin).
Conventionally, the glass substrate 302 and the common wiring board 307 are juxtaposed with the electrode terminals 303, 372 faced upward. Then the electrode terminals 303 and 372 are electrically connected to the output terminals 342 and input terminal 306 of the flexible wiring board 304 by means of an anisotropic conductive material 395 or solder (not shown), respectively. Also, as shown in FIG. 55, one end of the connector 308 is connected to the bus line 371 of the common wiring board 307, while the other end of the connector 308 is connected to a signal feed terminal (not shown) of the control board 311.
In operation, a signal is fed to the bus line 371 of the common wiring board 307 from the control board 311 via the connector 308. Sequentially through the bus line 371, the electrode terminal 372, and the input terminal 306, the signal is inputted to the drive IC 305 of the flexible wiring boards 304, 304', . . . . Then, the signal outputted by the drive IC 305 is applied to pixels through the output terminals 342 and the electrode terminals 303. Thus, the liquid crystal panel 320 is driven.
Recently, liquid crystal panels have been undergoing very severe competitive development, facing a demand for downsizing and weight reducing the liquid crystal panel modules. However, the above-described conventional assembling structure has both the common wiring board 307 and the control board 311 disposed and spaced from each other on side portions of the liquid crystal panel 320, thus inevitably resulting in a rather large size module. Further, since two types of large components, the common wiring board 307 and the control board 311, are provided, the resulting module is increased in weight, making a difficulty for weight reduction. Still further, the number of parts is increased so that the material cost is also increased. Yet, since the number of times of connection process is large, the man-hour required is increased, causing higher cost, disadvantageously.
Also, the larger the number of parts and the size, the more the module is affected by external force. Besides, the larger the number of times of connection process, the more the rate of occurrence of defectives increases. For these and other reasons, the reliability of the module is deteriorated to a further problem.